Obstacle plow



.Aug. 7, 1945.

A. J. HIGGINS, JR

OBSTACLE PLOW Filed July 24, 1944 3 Sheets-Sheet 1 Aug. 7, 5- A. .1.HIGGINS, JR

OBSTACLE PLOW Filed July 24, 1944 3 Sheets-Sheet 2 7, 1 945. A.JQHIGGINS, Jk

OBSTACLE PLOW 3 Sheets-Sheet 3 I Filed July 24, 1944 Patented Aug. 7,1945 UNITED PATENT DFFICE v :oBsrAcLE PLOW y: Andtewl'H-iggiins, Jr.,New Orleans, La. Application miner, 1944, SexialNo. 546;282 reclaims.(c1. arr-.219

This invention relates to :an nbsta'cle plow particularly designed asequipment for p'owered landing cra'ft in'fforcing aflanding on hostilebeaches defended by various types of offshore obstacles calculated totear the 'bottoms out of the landing 'craftror iotherwise preventthemfrom reaching the shore. The invention is especially adapted for thattype {of shallow 'draift broad bowed landing credit which slides up ontothe beach under power .for discharge of its personnel or cargo.

The general object of the invention is to pro- "vide an obstacle plow.of such width as to .em-

brace the entire width of the bow, arranged forwar'dl'y of the bow,"capable of ibeing Jhelcl inele- 'vated position out of water, in, whichposition it offers'no impediment to navigation, andadapted tobe'lowere'dto and held in vapositio'n'in .protec- "tiverelation to thesubmerged bottom with .its convergent obstacle engaging apex shallowlysubmerged.

Anotherobject of the invention-is [to provide an obstacle plow. asdescribed, pivotally mounted at the sides of the hul1,;permitting it tobe alternately elevated, or lowered to working position, with means .iorlocking it in working position soflthat it presents a positiveunyielding thrust to the obstacle-tube breached, and will not lift uponenga ement with the obstacle.

Aiu-rther object of the .inventionisto provide a pivotallymountedobstacle plow .as described, in which the locking means are readilyremoved or released so that the plOW. maybe; unlocked after the obstaclehas been cleared; permitting the .plow to lift automatically uponcontact with. the shelving beach so that the craft can i be .properlylanded. v

Still another :object of the invention is toprovide means for releasing"the connections ot-the plowiwit'h the =landin'g craft, permitting the.plow to be completely dropped from the craft, should iSllCh necessityarise.

A still further object of'the invention is to provide an obstacle plowhaving divergent fenders below the obstacle engaging apex, arranged inprotective relation to the submerged forward part of the craft fordivertingsuc'h portions "of the obstacleas may be overrun bythe'attacking" apex.

A *further object of the invention is 'to'make "the plow automatically"releasable irom the landing craft; upon its encountering an immovableobstruction such as an abruptly rising bank or shore. r

Other objects or the invention will appear "as the following descriptiono'f apreferred andi ractica-l embodiment thereof pro ceeds.

In the drawings which accompany and iform a part of the followingspecification, and throughout the several *figu'res "of which the samereference characters have 'been employed to :denote identical parts: i

'Figure 1 use side elevation o'i the .forward :portion of a landing'crai-tgshow ing 'thezobstacle plow in working position;

Figure 2 is a plan view or Figure 1;

Figure 3 is a cross-section through the con- 'necting means, taken alongthe line 3-3 of iEi'g- Figure '4 is "a"cross-section'takenalong the line.4-4?of'Figure3";

Figure -5'is a side elevation of the releasing winch;

' Figure '6 is a'n 'end'elevationof "the winch shown in Figure 5;

Figure '7 is apersp'ectlve "view of the locking bracket;

Figure 8 is a diagrammatic planota landing craft with obstacle plowattached, the forward ,portion "of the plow being omitted, showing aconvenient location for the releasing winch and the flexible connections-therefrom tothe plow;

Figure!) is aperspective'viewshowing the construction at the rear 'endof the side members.

Referring now in detail to the several figures,

thenumeral l represents a landin'g craft of the shallow drafttypejhavin'g the broad bowfi closed by a ramp 3, which-swings down *upon"the beach after the crafthas landecl, to permitthe discharge or thepersonnel or the mechanized equipment. Such craft are "employed inlanding upon hostile beaches "where there are no dock facilities, the

.craft s'liding'up upon the beach under power.

"suchbeaches "are frequentlydefended by offshore obstacles, the tops ofwhich are just submerged at high tide and calculated either to tear thebottom out of the landing 'craft or :to hang them up upon saidobstacles, to prevent them 'fromreach'ing the shore. Two-types of suchobstacles may be mentioned, barriers fabricated of logseitherdr-iveninto thecsea bottom-unweighted to keep them in place, orconcrete imasses resting upon the sea bottom, 'in which sections ofsteel rai1- are east with their sharp or jaggeden'ds upstanding.

The subject invention proposes to equip such landing "craft withaforwardly positioned obstacle plow which attacks such obstacles underthe powerof the craft, either rending or disintegrating the logbarriers, or turning them aside, 'or'upsetting or pushing aside thesteel rail barriers to provide a passage therebetween for the landingcraft. The plow in general is designated by the reference character 4.As illustrated, it consists of a pair of rearwardly divergent bars 5forming a working apex 6 at the front and separated sufficiently at therear to embrace the entire width of the bow of the landing craft. Sidemembers extend from the rear ends of the bars 5 substantiallylongitudinally along the sides of the landing craft, spaced therefrom,having pivotal connections with the sides of the landing craftrepresented by the coaxial pins 8 (see Figures 1, 2 and \3), the detailsof which connections will be described in due course. extend-toward therear beyond said pivotal connections to provide for holding and lockingthe plow in working position, as will presently be explained.

The plow comprises also the rearwardly extending midrib 9, secured tothe divergent bars 5 adjacent the apex 6, and extending divergentlyrearwardly below the horizontal plane of said side bars so as to formwith said side bars a trihedral angle at the apex. A pair of rearwardlydivergent fender bars l are connected to the midrib 9 at an intermediatepoint, and another pair of rearwardly divergent fender bars H, at itsrear end. Both pairs of fender bars lie in planes which divergerearwardly downward from the plane of the side bars 5. The divergentends of the fender bars H] are connected to the side members by thestruts l2 and the divergent ends of the fender bars II are connected tosaid side members by the struts I3 at points forwardly of the connectingmeans and the ends of the fender bars II are also connected to the sidemembers 1 rearwardly of the locking means by the upwardly inclinedextensions l4. The fender bars H) are also connected to the side bars bythe inclined struts l5. Thus, the plow forms a strong threedimensiongirder construction.

As illustrated, the obstacle plow and its appurtenant parts arefabricated by welding, a mode of construction which involves theemployment of The side members structural expedients which would not beresorted to under some other mode of construction. Since themanner ofmaking this obstacle plow is not particularly important to theinvention, these details peculiar to welding need not be described. Byway of example, the side bars 5 are welded to the side members at thejoint I6, involving the use of the strengthening members I1, which lapsaid joint and are welded to the adjacent members.

In order to connect the obstacle plow pivotally to the sides of thelanding craft, the latter is provided with the brackets, in generaldesignated by the reference character l8 and shown in detail in Figures3 and 4. Each bracket comprises a back plate l9 secured to the side ofthe craft in any suitable manner as by the rivet plugs 20, Figure 1.Since this plate is called upon to resist the thrust of the plow againstthe obstacle, the connection must be quite strong. For example, therivet plugs 20 may be four inches in diameter. A housing having the formof an inverted channel extends outwardly from the plate I9, said housingcomprising the spaced vertical inner and outer side plates 2| and 22connected by a top plate 23. Said housing is overlain by an inclinedbrace plate-24, connected at its upper side to the back plate l9 and atits lower side to the top of the outer side plate. 22. The brace plate24also serves as a protective cover for the .sheave25,

which is journaled on a pin carried by a lug 26 secured to the top plate23.

The side plates 2| and 22 are provided with vertical pin receiving slots21 for the pivot pins 8, which pass horizontally through the sidemembers 1 of the plow, forming extensions on both sides thereof. Saidpins are suitably secured to the side members as by welding.

Operable within the housing is the latch member, as a whole designatedby the numeral 28, consisting of the side plates 29 and 30, connected bythe angular bridge piece 3|. The side plates 29 and 30 are provided withjournal blocks 32 and 33 journaled in suitable bearing recesses in theside plates 2| and 22. The side members, including the journal blocks,are provided with the pin receiving slots 34. In the norma1 position ofthe latch member 28, shown in Figure 4, the slots 34 are at right anglesto the slots 21, so that the pin 8 is retained within the housing. Theside plate 30 of the latch member 28 is formed with a cable receivinggroove 35, in which lies a cable 36, the end of which passes through aneye 31 formed on the lower face of the side plate 30. The cable passesthrough a hole 38 in the top plate 23, around the sheave 25, throughregistering holes 39 and 40, respectively, in the back plate l9 and theside of the boat, from which point it may pass to the deck of thelanding craft, then about direction changing pulleys or fair-leaders 4|to Blge winch, designated as a whole by the numeral The winch is shownin detail in Figures 5 and 6 and comprises a base 43 having spacedbearings 44in which is journaled the shaft 45 of a drum and ratchetmember 46. The drum is preferably hollow and has a hole 41 for securingthe end of the cable 36, which is passed through the hole 41 and knottedon the inside of the drum. The winch includes a holding pawl 48 and awinding pawl 49 pivotally secu ed to the hand lever 50 which is rockableabout the shaft 45. By winding the cable on the drum 46 the latch member28 is rotated to a position in which the slots 34 coincide with theslots 21, whereupon the pin 8 drops out, disconnecting the plow from thelanding craft. Normally, when the cable 36 is unwound or released bylifting the holding pawl 48, the offset weight of the latch member 28returns it to the position shown in Figure 4.

It is noted from Figure 8 that the winch 42 simultaneously operatescables leading to opposite latch members, so that both pins 8 aresimultaneously released.

The means for positioning the obstacle plow in its lowered or rockingposition and for locking it in such position are located rearwardly ofthe connecting means and so placed as to give the side members and sidebars 5 of the plow a general downward inclination in a forwarddirection, whereby the Working end of the plow is submerged and the plowinterposed in protective relation to the submerged portion of the boathull. The locking means are shown in detail in Figure 7. Each consistsof a back plate 5| secured to the side of the landing craft by one ormore rivet plugs 52. Spaced upright side members 53 and 54 extend in atransverse direction outwardly from the back plate 5|. These support asemicylindrical socket member 55 adapted to receive the ends of theextended portions 56 of the side members The outer end of each socketmember 55 is obstructed by means of chordally disposed plates 51 securedthereto. Any other form of obstructive means would be the equivaready toattack the obstacle.

aesncco with a flat vertical clip 58 welded across the ex tension in itsvertical diametrical plane and having a rearwardly opening pin slot 59.Said clip extends between the spaced lug 60 formedon the rearward faceof the plate 53, and having rearwardly opening pin slots 6| with whichthe slot 59 and the clip 58' registers. Detainin springs 62 guard theentrances to the slots 6|. A double headed pin 63 may be pressed endwisea ainst the tension of the springs 62 into the aligned slots GI and 59to lock the obstacle plow in its working position. When it is desired toremove the locking pin 63, this may be readily done by pulling itthrough the open ends of the slots against the tension of the springs62.

The side members of the plow, including the extensions 56, are providedwith streamlined deflectors 64, to divert portions of the obstacle whichmay be sliding along the side members of a plow, from engaging anddamaging the respective connecting and. locking instrumentalitiesattached to the outside of the sides of the landins craft.

A block and fall 65 is connected to the obstacle plow at a convenient pint forward of its pivotal connection with the landing craft, the ropeof which may pass through the ramp and be conveniently located along thedeck. Normally,

when he craft is: navigated in open water the pin 63. is not in placeand the plow is, drawn up by the block and fall, swingin about itspivotal connection to a position against the bow portion or the craft,where it is entirely above the water line and offers no impediment tothe prog" ress of the craft. When the beach to be invaded isvapproached, the plow is lowered by. means of he block and fall, swingingabout th pivotal connection. 8 until the ends of the extensions 56 enterthe sockets 55, with the clips 58 between the lugs 60 and the slots 59and GI in alignment- The sockets 55. act as stops to determine the low-I errnostj. or workin position of the plow. Members of the. crew,reaching over the side of the boat. then put the pins. 63 in lace,looking the plow in its. working. position so. that it is now strihesthe obstacle under the full power of the landin crait, it either rends;or pushes aside the obstruction, the. latter being diverted. by the sidebars 5 and side members 1- 0f the plow, to. clear a path of sufficientwidth forthe passage of the landin craft through the barrier. Any partof the obstacle overrun by the plow is diverted laterally by thedivergent. fender bars Ill and H out. of the path of the submergedportion. of the hull. cleared. enough poll is. put: upon the block andfalt 65. to takethe weight of the plow ofiof the pins; 53,. which are.removed by crew members. The plow is then in position for landing; It isnoted that the apical portion 6 of the plow is upturnedso that it will.be upwardly deflected upon contact. with, the beach and not dig intothe; sand... As the. landin craft; rides up upon the; each, the plowautomaticall tiltsabout its pivotal onnections 8 and affords. no,resistance When the plow lmmediatel-y'upon the obstacle. having been totheproper landing of the craft. The ramp may then be let down over theplow and the personnel or equipment discharged over the ramp.

There may be times when the presence of the plow acts as a drawback, sothat it may be desirable to quickly disconnect it completely from thelanding craft. For example, a plow may occasionally become fouled uponthe obstacle so that the craft is hung up and unable to make a landingor get away. Under such circumstances the plow may be quicklydisconnected by cutting the rope of the block and fall and operating thewinch to cause the releasing member 23 to drop the pins 8. When the pins8 are out of the slots 21, a very slight forward movement of the craftwill release the pins 63 from the slots 62 and the landing craft isentirely free from the plow. Sometimes the beach may be so precipitousthat the plow would assume an elevated position, preventing the properdescent of the ramp, in which case it may be desirable to lose the plowbefore the landing craft finally grounds upon the beach. Occasionally itmay be desired to drop the plow in deep water, in which case, when therope of the blockand fall has been cut and the pins 8 released, the plowwill sink to a vertical position, whereupon the slots 59 will slip fromthe pins 63 and the plow be entirely freed from the landing craft. As afactor of. added flexibility in the use. of the obstacle plow, it ispreferred to make the pins 8 and 63 as shear pins so that if the plowencounters an immovable obstacle it may, according to the nature of theencountered obstruction, break the pin BI and ride over the obstructionor break the pin 8 and become released from the landing craft.

While I have in the above disclosure described what I believe to be apreferred and practical embodiment of the invention, it may beunderstood to those skilled in the art that the details of constructionas shown and described are only one of the 'many ways in which theinvention can be embodied, and not to be construed as limiting the scopeof the appended claims.

What I claim as my invention is:

l. Obstacle plow adapted to be mounted in front of. the bow of a landingcraft, comprising side members convergent forwardly to an apex andspaced apart. at the rear to a width greater than that of the bow andextending rearwardly along the sides of the bow,.means for pivotallyconnecting said plow to said landing craft on a horizontal transverseaxis at intermediate points of said side members, and stop means securedto said, landing craft rearwardly of said connecting means, engageablewith the rearwardly extending portions of said side members fordetermining the working position of said plow.

2 Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising side members convergent forwardly to an apex andspaced apart at the rear to a width greater than that of the bow, meansfor pivotally connecting said plow to said landing. craft at both sideson a horizontal transverse axis, and means for simultaneously releasingsaid plow from both its pivotal connections.

points of said side members, means for simultaneously releasing saidplow from both its pivotal connections and stop means secured to saidcraft rearwardly of said connection means, engageable with therearwardly extending portions of said side members for determining theworking position of said plow.

4. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising side members convergent forwardly to an apex andspaced apart at the rear to a width greater than that of the bow, meanfor pivotally connecting said plow to said landing craft, comprisinghearing members fiXed to said landing craft at opposite sides, andcoaxial transverse pins carried by said side members, journaled in saidbearing members, and means operable at will for releasing said pins fromsaid bearings.

5. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an openwork girder frame opposing minimum resistanceto water displacement, including a pair of side members convergentforwardly to an apex and spaced apart at the rear to a width greaterthan that of the bow, and pivotally connected to the landing craft topermit the plow to be raised or lowered, a median longitudinal memberextending from said apex downwardly and rearwardly divergent from thetransverse plane of said side members, a pair of fender bars convergentto an apex at a point in said median longitudinal member divergentrearwardly and downwardly, and struts connecting said fender bars tosaid side members, said plow having a working position in which theforward end is shallowly submerged and in which the fender bars are inprotective position forward of the submerged portion of the bottom ofthe craft.

6. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an obstacle engaging and bottom protecting memberforwardly convergent both transversely and upwardly, having side membersextending along the sides of the landing craft, means for pivotallyconnecting said plow to the sides of the landing craft at coaxialintermediate points in said side members, and stop means on the sides ofsaid landing craft above the inner end portions of said side members,engaged by the latter determining the working position of said plow inwhich the forward end is shallowly submerged, said plow being freelyswingable upward from its working position upon contact with a shelvingbeach.

7. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an obstacle engaging and bottom protecting memberforwardly convergent both transversely and upwardly, having side membersextending along the sides of the landing craft, means for pivotallyconnecting said plow to the sides of the landing craft at coaxialintermediate points in said side members, said connecting meanscomprising cooperating bearing and journal means carried by said sidemembers and landing craft, means operable at will for releasing saidjournal means from said bearing means for disconnecting said plow fromsaid landing craft, and stop means on the sides of said landing craftabove the inner end portions of said side members engaging the latter,determining the working position of said plow in which the forward endis shallowly submerged, said plow being freely swingable upward from itsworking position upon contact with a shelving beach.

8. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an obstacle engaging forwardly convergent memberhaving side members adapted to embrace the sides of the landing craft,intermediately pivotally connected to the sides of said landing craft,means engageable by the free end portions of said side membersdetermining the working position of said plow, said means beingconstructed and arranged to permit said plow to swing freely upward fromits working position, and means operable at will for fixing said plow inworking position.

9. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an obstacle engaging forwardly convergent memberhaving side members adapted to embrace the sides of said landing craft,intermediately pivotally connected to the sides of said landing craft,brackets fixed to the sides of said landing craft having portions abovethe free end portions of said side members, engageable thereby to holdsaid plow in normal working position so constructed and arranged as topermit said plow to swing freely upwardly upon engagement with ashelving beach, the free ends of said side members, and said bracketshaving apertures, aligned when said plow is in working position, adaptedto receive a pin for locking said plow in working position.

10. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an obstacle engaging forwardly convergent memberhaving side members adapted to embrace the sides of said landing craft,intermediately pivotally connected to the sides of said landing craft,brackets fixed to the sides of said landing craft having downwardlyopening sockets above the free end portions of said side membersengageable thereby to determine the working position of said plow butpermitting it to swing freely upwardly upon engagement with a shelvingbeach, each bracket .being provided with spaced lugs having transverselyaligned open ended slots with spring detents restricting the mouths ofsaid slots, the free ends of each side member being provided with aportion interdigitating with said lugs and having the open ended slotregistering with said lug slots when said plow is in working position,and a pin adapted to be manually pushed laterally past said detents intosaid aligned slots for locking said plow in working position.

11. Obstacle plow adapted to be mounted in front of the bow of a landingcraft, comprising an obstacle engaging forwardly convergent plow member,having side members adapted to embrace the sides of said landing craft,pivotally connected to the sides of said landing craft, the pivotalconnections comprising transverse coaxial pins carried by said sidemembers and brackets carried by the sides of said landing craft,latching members journaled in said brackets having open ended slotsreceiving and normally supporting said pins, means operable at will forrotating said latching means to bring said slots to a position in whichsaid pins are dropped from said latching means disconnecting said plowfrom said landing craft, means for lowering said plow to submergedworking position or raising it to an unsubmerged position, and means forlimiting the normal range of lowering movement of said plow to itsworking position.

12. Obstacle plow adapted to be mounted in front of the bow of a landingcraft comprising an obstacle engaging forwardly convergent plow memberhaving side members adapted to embrace the sides of said landing craftand pivotally connected to the sides of said craft, the pivotalconnection including transverse coaxial pins carried port and retainsaid pins in said bracket slots,

by said side members, and brackets carried by the 7 means for rotatingsaid latching means to bring side of said landing craft, said bracketshaving the slots of said latching means into alignment downwardlyextending pin receiving slots open at with the bracket slots wherebysaid pins are their lower ends, latching members journaled in 5gravitationally dropped from said aligned slots, said brackets havingopen ended pin receiving disconnecting said plow from said landingcraft. slots cooperating with said bracket slots in the normal positionof said latching means, to sup- ANDREW J. HIGGINS, JR.

